Bio-degradation of polyurethane based on bio-epoxy

This research is focused on the resistance to thermal, photo and bio-degradation of polymer thin films fiom renewable resources based on virgin and waste vegetable cooking oil from lndustri Kecil Sederhana (IKS's). Vegetable and waste vegetable oil polymers were grouped as virgin oil polymer (VOP) and waste oil polymer (WOP) thin films were prepared by adding bio-monomer (lgm; 0.5 gm equivalent weight with polyol) with an appropriate amount of 4, 4'-methylen-bis-(phenylisocyanate) (MDI) which thickness was 1 10-200pm *O.OI pm. VOP and WOP thin films were tested for its resistance to thermal, photo and biodegradation exposure for an extended period of time. The techniques utilized were principally infra-red (R). The degradation of which upon thermal exposure was tested by measuring the change in the carbonyl index, CI for WOP and VOP thin films. Thermal exposure was measured at 50°C, 100°C, 150°C and 200°C up to 600 minutes. As the temperature and the exposure time increased, the CI also increases for both WOP and VOP at given temperature and 600 minutes from initial value of WOP is 0.296 to 0.391, 0.380, 0.413 and 0.427, meanwhile the initial value for VOP is 0.417 to 0.507,0.45, 0.433 and 0.44 respectively. The increased in CI formation for polymer after thermal exposure is proportional to the number of chain scissions that occur in the polymer thin films associated with the scission of the (-NHCO-O-), The absorption band of carbonyl groups near 1738 cmwas broadened on increasing the heating time; also shoulders appeared on the main peaks in a range at 1805-1800 cm*', The shape of the peaks for all spectra thin films are fairly broad suggesting that more than one functional groups are formed within the carbonyl group (C=O) family such as aldehydes, ketones, acids, esters, amides and anhydrides in the range of 1805-1 704 crn-'. The TGA curves of the WOP and VOP display three distinct regions of weight loss. The size of the peak at higher temperature was found to be correlated with the amount of soft segment that c. a. n be attributed to the alkyl chain. It was established previously that the amount of weight loss at the lower temperature is well correlated with the amount of hard segment, suggesting that the degradation process starts in the hard segment based on the MDI component. Biodegradability of polymer thin films was measured using soil burial test according to EN IS0 846:1997. The percentage weight loss of VOP thin film in compost soil burial test was significantly greater than those in peat soil burial test. IR-changes, yellowing of tensile WOP thin films as a result of photo-degradation upon equatorial weathering were studied. As a conclusion, mechanical properties of polymer thin films for WOP md VOP can be strongly influenced by photo-oxidation upon equatorial weathering exposure. The ductility disappears and the strength and strain at rupture strongly decrease at over 35%. The active participant of OH group with isocyanate was lead to the creation of more stress point, thus, lower energy needed for WOP thin films to bring to failure. Moreover, the occurrence of surface damage enhances the degradation of these mechanical parameters

Deposition and Characterization of Cobalt doped Titanium Dioxide Thin Films using Sol-gel Method

Thin films become more importance and a lot of research and studies have been done toward the improvement and achievement. In this study, the new finding of deposition Cobalt (Co) doped TiO2 thin films have been prepared by sol-gel method onto a glass substrate at room temperature for enhancement of optical properties. The effect of Co doped TiO2 thin films have been studies. The different concentration of Co was varied from 1 wt %, 2 wt % and 3 wt % dopant. The deposition of Co doped TiO2 was prepared by using sol-gel method and spin coating technique on the glass substrate. The obtained films have been annealed at 400 oC, 500 oC, and 600 oC for 2 hours and were investigated. X-ray diffraction (XRD) peaks revealed that the films exhibit showed that Co:TiO2 films are anatase crystalline structure at orientation (101). The surface morphologies of the Co:TiO2 thin films were evaluated by Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM). The calcination temperature and content of Co dopant gave a different size of particle and grain boundary. Root Mean Squared (RMS) roughness values increase by increasing the molar ratio of dopant. While, as the calcination temperature increases, the RMS also increasing. The optical properties were studied by using UV-visible spectroscopy (UV-Vis) with a wavelength range of 300 nm to 1000 nm. The calculated optical band gap decreases with increasing of Co doping

The Effect of Water Bath Temperature during Electrochemical Deposition of Zinc Oxide

Nanostructure Zinc Oxide (ZnO) is widely applied in various fields such as optoelectronics, sensors, transducers and biomedical sciences. Nowadays, there are many methods that can be used to produce ZnO thin film such as electrochemical deposition. This method is a process of converting or forming an oxide layer on the metal surface. The purpose of this research is to study the effect of water temperature on the morphology of ZnO during the electrochemical deposition process. ZnO nanostructures obtained after electrochemical deposition process is carried out at different water temperatures and a constant current density. Electrochemical deposition process was carried out when the water temperature reached 60, 65, 70, 75 and 80oC. During the deposition process, 0.05 M/L zinc nitrate is used as a single electrolyte. The analysis conducted is divided into four categories, namely FESEM, XRD, EDX and UV-Vis. As a result, the suitable water bath temperature for forming the ZnO morphology with an electric current density of 4 mA/cm2 is at 75oC and at this temperature it has a higher value of composition mass where is 0.61 % compare with other temperature. From the UV-Vis analysis, it shows the value of band gap is 2.87 eV when the temperature of water bath was 75oC. Various studies were conducted to produce ZnO nanotubes because it provide different forms of reaction temperature at constant current densities

Rheological and thermodynamic behaviour of PSf/ZnO: Effect of zinc oxide

Zinc oxide synthesis normally involve zinc precursor and reduction during the preparation. To improve the dispersion of nanoparticle, the ZnO synthesis is the most promising option since the particles can stabilize in dope solution. However, the process of ZnO synthesis required the addition of polar precursor and reduction agents which are expected to influence the rheological and phase inversion properties of membrane dope solution. It is worth to mention that the rheological properties and phase inversion behaviour of the dope solutions play a critical role in determining the membrane morphology and separation performance. The PSf/ZnO dope solution was prepared via in-situ synthesis using three different precursors and reducing agents. The concentration was varied from 0 wt. %, 1 wt.% and 2 wt.% before dissolving in N-Methyl-2-pyrrolidone (NMP) as it will completely dissolved together. Three different precursors used were Zinc Chloride, Zinc Nitrate and Zinc Acetate while Sodium Borohydride, Hydrazine Hydrate and Urea are three different reduction agents. The thermal stability of the dope solutions was analyzed using cloud test measurement and the rheological properties were measured using viscometer toward the viscosity of the dope solution. Thermodynamic stability analysis denotes that that the hydrazine hydrate has the lowest water percentage for 15 wt.% of PSf which is 3.30 %. Meanwhile, zinc acetate with hydrazine hydrate have the lowest water percentage for 15 wt.% PSf which is 1.59 %. This also shows that the zinc chloride binodal line nearly to the solvent/polymer axis which might resulted on faster demixing rate and miscibility gap become shorter. Urea is nearest to binodal line. Viscosity test results to highest viscosity of urea as reducing agent in dope solution. Moreover, it shows that the PSf/ZnO solution have Newtonian behaviour. As the concentration of Zinc Oxide increases, the viscosity increases at the room temperature

Evaluation of corrosion and wear behaviour of nickel tungsten carbide electrodeposited with different tungsten carbide concentration and current density

Cermets (ceramic-metal) materials have been popular for wear and corrosion application due to their ability to withstand both conditions. In current work, cermets tungsten carbide-nickel (WC-Ni) composite coating has been deposited using direct current (DC) electrodeposition in Watt’s bath on mild steel. The current density were varied at 0.08 Acm-2 , 0.14 Acm-2 and 0.20 Acm-2 while others parameter i.e. bath temperature and stirring rate were remain constant. Three carbide concentrations were used that are 15 g/l, 20 g/l and 25g/l. This work is focusing on determining the effect of current density and carbide concentration to the wear and corrosion behaviour of WC-Ni cermet coating. The surface morphology, microstructure and elemental composition were analysed using scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS). The wear and corrosion behaviour were evaluated using weight loss methods and three electrode electrochemical tests respectively. The abrasive wear was done against 800 grit silicon carbide paper. While for corrosion test, two types of electrolytes that were used are 0.5 M sulphuric acid and 3g/l sodium chloride at room temperature. The micro-hardness of the coating was analysed using Vickers micro-hardness tester with 100g load. It is found that, the wear resistance increases with increasing of carbide content and current density. The corrosion resistance was also increase with increasing of carbide content. For current density, it is slightly decrease of corrosion resistance after deposition at 0.20 Acm-2 due to uneven distribution of carbide. The hardness of the cermet coatings were increase with increasing of carbide content and current density. It can be concluded that with 25g/l carbide and at 0.14 Acm-2 current density shows the optimum combination to achieve high wear and corrosion resistance

Effect of calcination temperature on (N, Fe) doped TiO2 nanoparticles

TiO2 is one of the most promising photocatalysts that is widely used for environmental clean-up due to its ability to degrade organic pollutants in air or water in the presence of UV light irradiation. In this study, the sol-gel method followed by calcination process was employed to synthesize N, Fe doped TiO2 nanoparticles. The effect of calcination temperature on the structural, morphology and optical properties of the as-prepared samples was analyzed. Titanium tetra isopropoxide (TTIP) was used as Ti precursor and urea and ferric nitrate nonahydrate were the employed precursors to obtain N and Fe, respectively. X-ray diffraction pattern displayed a transformation of anatase structure to biphasic of anatase and rutile structure as the calcination temperature was increased from 300 to 700 °C. FESEM images indicated an agglomeration of particles with the grain size was estimated at 50-170 nm. UV-Vis analysis revealed that the increment of calcination temperature induced a red shift in the absorption spectra from 485 nm to 664 nm. Hence, the results indicate that N, Fe doped TiO2 is a highly potential visible-driven photocatalyst to degrade pollutants under the presence of visible light irradiatio

Seashell structure under binder influence

Since the very beginning, evolution on protective materials keep going on where the material utilized as a part of plate armour continue changing, from steel, Kevlar, ceramic and the materials that can give better impact and benefit to the user. A study has been led to distinguish either seashell can be one of the fundamental source to produce protective material due to its properties calcium chloride. Seashell is crushed and chipped using variable speed rotor mill and is compressed into specimen shape. A batch of samples is tested made from seashells that mix with three different binder i.e. water, kaolin and polyethylene glycol (PEG). One batch of samples is dried at room temperature which another batch of samples are sintered at elevated controlled temperature before testing to determine their mechanical properties results. Result shows that at high temperature, specimen with water and PEG gives the highest value of Young’s modulus and ultimate strength compared to sample without temperature effect. However, temperature effect shows no differences on kaolin samples compared to room temperature curing sample